A method for detecting a face region in an image is known in the related art, which estimates the size of the face from magnification set for the shooting and calculates the size of a skin-colored region in the image. This method allows a region of the face to be detected in the image by comparing the estimated face size and the skin-colored region size (refer to patent reference literature 1).
Patent reference literature 1: Japanese Laid Open Patent Publication No. H07-306483